So-called “screen widgets” are sometimes implemented by software applications to enable a user to interact with an application in an intuitive way. A screen widget typically includes one or more images to display information or choices to the user. The user typically interacts with a widget image by “gesturing” relative to the image. For example, the user may point, click, or drag with a mouse or other pointer device or via key presses. A computer code module associated with the widget detects the user gestures and interprets particular gestures relative to the images as pre-defined types of user inputs.
Some widgets are designed to view and/or select from a set of items or choices or to scroll within a range of a variable. Such widgets may include check boxes, radio buttons, drop-down lists, and sliders. A value-selection widget such as a slider may be particularly useful for quickly examining and choosing from a range of numbers. The numbers may represent a selectable or viewable range of a variable such as price in the field of commerce, population in the field of demographics, or focal length in the field of optics, for example.
Factors that may affect the ease of use of a slider widget may include the magnitude of the upper and lower limits of the range of values to be selected from, the granularity of the step-changes from one value to the next, the length of the slider bar in screen pixels, and the sensitivity of the mouse or other pointer device. So, for example, an eight centimeter-long slider used to select from among 40 variable values may be easier to use than a three-centimeter slider used to select from among 10,000 values. The latter slider design may result in awkward selection because the number of values per linear slider distance is greater than can be comfortably controlled with a mouse or other input device of a given sensitivity.